EP0439397B1 - Water level control in a household appliance and machine provided with such a device - Google Patents

Description

The present invention relates to a device for regulating the water level of a tank of a household appliance, and device provided with such a device.

A household appliance such as a dishwasher, a washing machine usually comprises a tank containing a liquid or a washing or rinsing water, the volume of which is adjusted by means of a level control device. This device comprises either a float chamber or a compression chamber which actuates an electric switch for controlling a solenoid valve for supplying water to the tank of the appliance. A float chamber or a compression chamber is generally mounted in vessels communicating with the tank of the device so that the level of liquid or water in this room is a function of the level of liquid or water in this tank. A liquid or dirty water in the tank can thus enter this float chamber or compression chamber and clog it. In order to prevent this contamination, a known solution consists in forming a reservoir of liquid or clean water and placing it between the tank of the apparatus and the device for regulating the water level. The content of this reservoir of liquid or clean water acts as a buffer which separates the liquid or dirty water in the tank, from the liquid or clean water in the float chamber or compression chamber of the level control device. However, under vibrations from a device in operation or by diffusion, the liquid or dirty water in the tank of this device ends up mixing with the liquid or clean water in this tank and comes to contaminate this float chamber or compression chamber of this level regulation device. Such a machine is described in European patent application No. 86 104780 from Bosch-Siemens.

The aim of the present invention, to avoid this drawback, is to provide a device for regulating water level in the tank of an appliance where the liquid or dirty water in the tank does not contaminate the float chamber or compression chamber during the operation of this device.

The invention also relates to a household appliance fitted with such a device for regulating the water level, mounted in communicating vessels with its tank.

According to the invention, a device for regulating the water level of a tank of a household appliance is characterized in that it comprises a clean water distributor comprising two outlet channels in parallel each having a capacity of evacuation of all the water received by this distributor, namely a priority outlet channel operating in priority by passing through a control chamber which opens or closes this priority channel according to the absence or presence of trapped air and compressed by a rise of water in this control chamber and a substitution exit channel working to replace this priority exit channel during a progressive closure of the latter by this control chamber.

Other forms of execution are the subject of the dependent claims.

• la figure 1 représente une vue schématique et partielle d'un lave-vaisselle muni d'un dispositif de régulation de niveau d'eau selon l'invention, et
• la figure 2 représente, à une autre échelle, une vue schématique et partielle du dispositif de régulation de niveau d'eau de la figure 1.

To better understand the invention, an embodiment is illustrated below, illustrated by an attached drawing, in which:

• FIG. 1 represents a schematic and partial view of a dishwasher fitted with a device for regulating the water level according to the invention, and
• FIG. 2 represents, on another scale, a schematic and partial view of the device for regulating the water level of FIG. 1.

A household appliance such as a dishwasher 1, according to an exemplary embodiment of the invention, schematically and partially illustrated in FIG. 1, comprises a body 2, a tank 3 in which are mounted baskets for dishes 4, 5 , sprinkler reels 7,8 and a device for regulating the water level 10. This device for regulating water level 10 is mounted in an available space between the tank 3 and the bodywork 2 and in vessels communicating with this tank 3.

The household appliance 1 is supplied with clean water by a source E by means of a pipe 11 through a pneumatically triggered safety valve 12 and a solenoid valve 13 mounted in series on this pipe 11 and the level control device 10 The valves 12 and 13 can be replaced by a pneumatic and electric double trigger valve of a known type.

According to the invention, a device for regulating the water level 10 of a tank 3 of a household appliance 1 comprises a distributor of clean water comprising two outlet channels in parallel each having a capacity for discharging all of water received by this distributor, namely a priority outlet channel operating in priority by passage through a control chamber which opens or closes this priority channel according to the absence or presence of air trapped and compressed by a rise of water in this control chamber and a substitution exit channel working in replacement of this priority exit channel during a gradual closing of the latter by this control chamber.

The clean water distributor with two outlet channels comprises in its priority outlet channel a nozzle whose holes are calibrated to define a predetermined maximum flow rate, and between its two outlet channels a shoulder defining a water level or a water spillway threshold in the water dispenser above which its substitute outlet channel has entered into operation in place of its priority outlet channel.

The two-way water distributor is supplied by a stream of clean water without turbulence and at a constant predetermined flow rate.

In the example illustrated in Figures 1 and 2, the device for regulating the water level 10 of the tank 3 of the dishwasher 1 comprises in its body, three partitioned spaces which are substantially vertical and parallel and of different heights 30, 47, 70 vented respectively by a duct 31 , an orifice 32 and a siphon 43 formed in their upper parts and connected at points 37 and 39 of their lower parts in vessels communicating with the tank 3 by connecting pipes 44 and 45. Above the air space lowest free 70 are formed a float chamber 16 whose float is indicated at 15 and a water drainage system 20 which is constituted by a siphon 69 connecting a lower part of this float chamber 16 and the space lowest open air 70.

A clean water distributor 40 having two outlet channels in parallel 41, 42 is produced at the level of the float chamber 16 between the highest open air space 30 and the medium height free air space 47 This water distributor 40 is provided with an inlet open upwards in the upper part of the highest open air space 30, with a priority outlet channel with nozzle 41 opening into a control chamber 38. open downwards in the medium height open air space 47, and a substitution exit channel 42 opening in the float chamber 16.

A clean water supply system 18 for this water distributor 40 is formed in the highest free air space 30. This clean water supply system 18 comprises a water inlet member 33 and at least one overflow and flow regulation tank which are arranged above this clean water distributor 40.

In the example illustrated, the clean water supply system 18 comprises two superimposed tanks with flow control 51 and 52 superimposed.

In the water level control device 10, on the one hand is mounted an electric switch for normal shutdown 25 of the supply of clean water to the tank 3 actuated by the float 15 for closing the supply solenoid valve 13, and on the other hand a safety stop system 29 for the supply of clean water to this tank 3 is produced.

In the supply system 18, the clean water inlet member 33 comprises a water intake pipe 34 connected by one of its ends to the clean water inlet pipe 11 and provided with its other end of two parallel outlets, namely a main outlet opening 35 and a secondary outlet pipe 36 having a diameter smaller than that of the water intake pipe 34. The main outlet opening 35 of the pipe d clean water inlet 34 is intended to supply clean water to the water distributor 40 at a constant predetermined flow rate while the secondary outlet pipe 36 discharges the excess water coming from the water intake pipe 34 downwards, through the pipe 44 in the tank 3. The diameter of the main outlet opening 35 of the clean water inlet pipe 34 and that of the parallel outlet pipe 36 are preset to obtain this pred flow fraction with clean water at the main outlet opening 35.

When the liquid or water in the tank 3 has not yet reached its normal filling level, all the water coming from the main outlet opening 35 of the water intake pipe 34 and entering the distributor water 40, freely crosses the priority nozzle 41 of this distributor 40, then the control chamber 38 which is open at the bottom and finally the connection pipe 45 to enter the tank 3 and help fill it. The tank 3 and the water level regulation device 10 being in communicating vessels, an increase in the level of liquid or water in the tank 3 is simultaneously accompanied by a corresponding rise in the level of liquid or water in the air spaces. free 30, 47, 70 of the level regulating device 10. When the liquid or water in the device 10 reaches a level F which corresponds to a level slightly below a level normal filling of tank 3 with water, this mass of liquid closes the bottom of the control chamber 38 and prevents the trapped air in this chamber from leaving. As this level of liquid or water rises in the device 10 consequently in the control chamber 38, the trapped air in this chamber which is more and more compressed is opposed more and more strongly to the flow of clean water through the nozzle path 41 in this control chamber 38 until the water coming from the supply system 18 and entering the distributor 40 is forced to take the path substitution outlet 42, enter the float chamber 16, fill the latter and raise the float 15.

In the clean water distributor 40, each of the two parallel outlet channels 41, 42 has a maximum flow rate at least equal to the constant predetermined flow rate of the water flow without turbulence provided by the supply system 18.

As soon as the liquid or water in the device 10 reaches a level N which corresponds to a normal level of filling with water in the tank 3, the float 15 actuates the electric switch 25 which closes the solenoid valve 13 of the inlet pipe 11 and stops the water supply to the tank 3 and to the water level control device 10.

To avoid the creation of turbulence in the water supplying the water distributor 40, one or more superimposed tanks with overflow and with flow regulation 51, 52 are arranged between this water distributor 40 and the opening of main outlet 35 of the clean water intake pipe 34. The overflow tanks 51, 52 respectively comprise in their upper part a weir edge 54, 55 which maintains at each instant in each of these tanks a constant individual quantity of clean water, and in their lower part a flow opening 57, 58 with preset diameter, which makes it possible to obtain at the inlet of the water distributor 40 a stream of feed water at a constant flow rate predetermined and without turbulence.

A deflector 60 may be disposed at the inlet of the water distributor 40 in the vicinity of the flow opening 58 of the adjacent overflow tank 52 to reinforce the prevention of the creation of turbulence in this same water dispenser 40. The nozzle of the priority channel 41 includes holes with calibrated diameters whose total sum of flows under a water height h less than the height H of the weir threshold 65 is predetermined equivalent to the flow of the flow opening 58 of the adjacent overflow tank 52 so that all the clean water coming from this tank 52 through this flow opening 58 takes the only priority flow path with nozzle 41 from the water distributor 40 during filling with clean water from tank 3 of the apparatus and therefore before the level of liquid or water in the level control device 10 reaches level F and before this liquid or water closes the lower part from the room control 38. Until this time, the float chamber 16 is not supplied with water by this distributor 40.

As soon as the liquid or water in the level control device 10 closes the lower part of the control chamber 38, the air trapped in this chamber is compressed and prevents the flow of water through the nozzle of the priority channel 41. As the level of liquid or water rises in the tank 3 and in the level control device 10, the air trapped in the control chamber 38 is more and more compressed and is increasingly opposed to the flow of water through the priority channel 41. During this time, the water distributor 40 continues to be supplied with water coming from the overflow tank 52 to through opening 58 with the same flow. The water level rises in the distributor 40 and as soon as it exceeds the overflow threshold formed by the shoulder 65 of the wall of the distributor 40, the water flows into the float chamber 16 through the outlet channel substitution 42 of this distributor 40.

When the level of liquid or water in the device level regulator 10 reaches a level N corresponding to the normal level of filling with water in the tank 3, the float chamber 16 is also filled to a level A which allows the float 15 to rise to its position shown in broken lines where it actuates the electric switch 25 which closes the solenoid valve 13 of the water inlet pipe 11 and thereby cuts off the supply of clean water to the tank 3.

Thus, thanks to this water supply system 18, the float chamber 16 is only supplied with clean water. Dirty water from the tank cannot enter the float chamber 16 to foul it.

The water evacuation system 20 from the float chamber 16 comprises a siphon 69 one end of which is disposed near the bottom of the float chamber 16 and the other end opens into the space 70 of the lower part of the level control device 10 which is in communication with the tank 3 through the pipe 45, the space 70 being at a level lower than that of the float chamber 16.

In the example illustrated in FIG. 2, the siphon 69 of the water evacuation system 20 is formed in superposition and in parallel with the air siphon 43 of the space 70 of the device 10. The intake siphon in air 43 of space 70 comprises an open end in the upper part of space 70 and one end disposed near the bottom of the float chamber 16.

When the tank 3 is emptied, which is in communicating vessels with the level control device 10, the liquid or water in the device 10 is also evacuated and its level drops from its position N downwards.

In its descent, this liquid or water creates in the space 70 a depression which sucks the water from the float chamber 16 through the siphon 69 to evacuate it.

Indeed, so that the depression which is created on the surface of the water contained in space 70 when the level in the tank drops, can draw the water in the siphon 69 from level A to the elbow (high point) of the siphon then, without decohesion of the liquid vein in the downstream descending part to the bottom of the siphon in communication with space 70, the section of the channel 69 is dimensioned relatively small so that the capillary forces retain the liquid vein without it splitting. However, at the end of the siphoning, the air has entered the siphon 69 and mixed with the water, and a randomly divided vein of water is formed. During a subsequent filling and if the air intake siphon 43 did not exist, the fractions of standing water stream remaining in the siphon offer resistance, precisely because of capillary forces, to the evacuation of the air. accumulated at the top of space 70.

Under these conditions, the water level in the space 70 at the end of this filling remains notably below the level N and during a subsequent emptying, the depression created in the space 70 is no longer sufficient to draw the water column in the siphon 69 up to the high point or bend of this siphon 69.

According to the invention, the second siphon 43 which is formed in superposition and in parallel with the siphon 69 and which has a relatively larger passage section than that of the siphon 69 and not subject to being blocked by a fractionated stagnant vein of water thus allows the air accumulated in the space 70 during this filling to be evacuated and the water to rise to the normal level N. When the float chamber 16 is emptied, it does not matter that this second siphon 43 starts or not since this siphon 43 cannot break the vacuum created in space 70 by venting it before the water level descends in the float chamber 16, below the end of the siphon 43. During this time, the siphon 69 is already primed and continues to empty the float chamber 16.

According to an alternative embodiment not shown, the siphon 43 is omitted and the siphon 69 comprises an ascending branch having a predetermined section preventing a formation of a fractionated stagnant vein of water and a descending branch having at each of its ends a portion of predetermined section narrowed in order to slow the flow without causing a lasting obstruction of this branch of the siphon by a fractionated stagnant vein of water . The siphon 69 thus serves both as a water evacuation system 20 from the float chamber 16 and as a means of venting the space 70 of the water level regulation device 10.

The safety shutdown system 29 for the water supply to the household appliance 1 comprises a pressure chamber 72 formed in a lower part of the level control device 10 and placed in communication with both an upper part of the medium-height open space 47 through a passage 75 provided with an overflow edge 76 and with the float chamber 16 through a passage 78 also provided with an overflow edge 79 and provided at its bottom with a pneumatic triggering device 80 of the safety valve 12. The overflow edges 76 and 79 are at heights which are respectively above the levels N of liquid or water in the open air spaces 30, 47, 70 and A of water in the float chamber 16.

When the liquid or water in the tank 3 reaches the normal filling level, the water also arrives at level A in the float chamber 16 and at level N in the open air spaces 30, 47, 70 and the float 15 operates the switch 25 to close the solenoid valve 13 and stop the water supply to the tank 3. At this instant, if the solenoid valve 13 breaks down or the electric switch 25 does not work, the water continues to arrive via the pipe 11 and supplying both the tank 3 and the level control device 10. The liquid or water in the float chamber rises, overflows the overflow edge 79 overflows the passage 78 enters the chamber pressure 72 and forms a column of water there, the pressure of which acts on the control device pneumatic release 80 which closes the safety valve 12 and stops the water supply to the tank 3 and to the level control device 10.

Thus, at no time, the liquid or dirty water for washing or rinsing in a tank can enter the float chamber 16, cause fouling or disturbance of the movement of the float 15 and cause a loss of precision in the operation of the level control device 10.

To improve the operation of the level control device 10, a deflector 82 can be arranged in the control chamber 38 on the path of the water flow through the nozzle of the priority channel 41 to avoid creating there. turbulence in the liquid or water.

Claims (12)

1. Device for regulating the level of water of a tank of an electrical household appliance, characterized in that it comprises a clean water dispenser (40) including two parallel outlet channels (41, 42) each one having the capacity to evacuate all the water received by this dispenser, namely a priority outlet channel (41) operating in priority mode by passing through a control chamber (38) which opens or closes this priority channel (41) depending on an absence or presence of air trapped and compressed by a rise in water in this control chamber (38), and a substitution outlet channel (42) working by replacing this priority outlet channel during progressive closure of the latter by this control chamber (38).
2. Device according to Claim 1, characterized in that the clean water dispenser (40) with two outlet channels comprises, on the one hand, in its priority outlet channel (41) a regulating nozzle and, on the other hand, between its two outlet channels (41, 42) a shoulder (65) defining an overspill threshold or level for water in the dispenser, above which its substitution outlet channel (42) comes into operation in the place of its priority outlet channel (41).
3. Device according to one of Claims 1 and 2, characterized in that it comprises a clean water supply system (18) which supplies the water dispenser (40) with two outlet channels with a stream of clean water without turbulence, and according to a constant predetermined flow rate.
4. Device according to Claim 3, characterized in that it comprises a clean water dispenser (40) each of whose parallel outlet channels (41, 42) has a maximum flow rate which is at least equal to the constant predetermined flow rate of the water stream without turbulence supplied by the clean water supply system (18).
5. Device according to one of Claims 3 and 4, characterized in that the clean water supply system (18) comprises, on the one hand, at the inlet, a water inlet member (33) giving a stream of clean water through an outlet opening (35) and, on the other hand, between this water inlet member (33) and the water dispenser (40) at least one container with an overflow and with flow rate regulation (51 or 52) which, fitted with an edge for overspill when overflowing (54 or 55) in its periphery and with an outflow opening with preset diameter (57 or 58) in its lower part, supplies water to the water dispenser (40) using a stream of water without turbulence and at a constant predetermined flow rate.
6. Device according to one of Claims 1 to 5, characterized in that it comprises in its body three substantially vertical and parallel partitioned spaces (30, 47, 70) at different heights venting respectively by a pipe (31), an orifice (32) and a syphon (43) formed in their upper parts and connected in their lower communicating-vessel parts to the tank (3) of the electrical household appliance by connection hoses (44, 45), a float chamber (16) located above the lowermost venting space (70), a clean water dispenser (40) with two outlet channels arranged at the height of the float chamber (16) between the uppermost venting space (30) and the medium-height venting space (47) and provided with an inlet which opens upwards into the uppermost venting space (30), with a priority outlet channel (41) opening out into a control chamber (38) which opens downwards into the medium-height venting space (47), and with a substitution outlet channel (42) opening into the float chamber (16), a clean water supply system (18) for this dispenser (40) produced in the uppermost venting space (30) with its water inlet member (33) and its overflow and flow rate-regulation containers (51, 52) arranged above this clean water dispenser (40) with two outlet channels, a system (20) for evacuating water from the float chamber (16) including a syphon (69) connecting a lower part of this float chamber (16) to the lowermost venting space (70), an electric switch (25) for normally cutting off the supply of clean water to the tank (3) of the electrical household appliance, actuated by a float (15) of the float chamber (16) so as to close a water supply solenoid valve (13), and a safety system (29) for cutting off the supply of clean water to this tank (3) intended to close a safety valve (12).
7. Device according to one of Claims 1 to 5, characterized in that it comprises in its body three substantially vertical and parallel partitioned spaces (30, 47, 70) at different heights venting respectively by a pipe (31), an orifice (32) and a syphon (69) formed in their upper parts and connected in their lower communicating-vessel parts to the tank (3) of the electrical household appliance by connection hoses (44, 45), a float chamber (16) located above the lowermost venting space (70), a clean water dispenser (40) with two outlet channels arranged at the height of the float chamber (16) between the uppermost venting space (30) and the medium-height venting space (47) and provided with an inlet which opens upwards into the uppermost venting space (30), with a priority outlet channel (41) opening out into a control chamber (38) which opens downwards into the medium-height venting space (47) and with a substitution outlet channel (42) opening into the float chamber (16), a clean water supply system (18) for this dispenser (40) produced in the uppermost venting space (30) with its water inlet member (33) and its overflow and flow rate-regulation containers (51, 52) arranged above this clean water dispenser (40) with two outlet channels, a system (20) for evacuating water from the float chamber (16) consisting of the same syphon (69) for venting the space (70), connecting a lower part of this float chamber (16) to this lowermost venting space (70), an electric switch (25) for normally cutting off the supply of clean water to the tank (3) of the electrical household appliance actuated by a float (15) of the float chamber (16) so as to close a water supply solenoid valve (13), and a safety system (29) for cutting off the supply of clean water to this tank (3) intended to close a safety valve (12).
8. Device according to Claim 7, characterized in that the syphon (69) which serves both as a means for venting the space (70) of this device, and as a system (20) for evacuating water from the float chamber (16) comprises a rising branch having a predetermined cross-section preventing a formation of a stagnant broken up stream of water, and a descending branch having, at each of its ends, a part with a predetermined narrowed cross-section for the purpose of slowing the flow rate without giving rise to a lasting obstruction of this branch by a stagnant broken up stream of water.
9. Device according to one of Claims 5 to 8, characterized in that in the clean water supply system (18), the clean water inlet member (33) comprises a water intake pipeline (34) connected by one of its ends to a bypass pipe (14) of a clean water inlet pipeline (11) and provided at its other end with two parallel outlets, namely a main outlet opening (35) intended to supply clean water with a predetermined flow rate to the water dispenser (40) through the overflow and flow rate regulation containers (51, 52), and a secondary outlet pipe (36) having a diameter which is less than that of the water intake pipeline (34) and intended to evacuate, through a linking hose (44) into the tank (3) of the electrical household appliance, the excess water coming from the water intake pipeline (34).
10. Device according to one of Claims 6 and 7, characterized in that the safety system (29) for cutting off the water supply to the tank (3) of the electrical household appliance comprises, on the one hand, a pressure chamber (72) formed in a lower part of the water lever regulating device (10), made to communicate both with an upper part of the medium-height venting space (47) through a passage (75) which is provided with an edge (76) for overspill when overflowing, and with the float chamber (16) through a passage (78) which is provided with an edge (79) for overspill when overflowing, and intended to form a pressurized water column with the overspill water from overflow of these overspill edges (76, 79) which comes respectively from the medium-height venting space (47) and from the float chamber (16) and, on the other hand, a pneumatically triggered actuating device (80) mounted in the bottom of this pressure chamber (72) and intended to be actuated by this pressurized water column in order to close a safety valve (12) which cuts the water supply to the tank (3) as soon as the normal water filling level of this tank is exceeded.
11. Device according to one of Claims 1 to 7 and 9, characterized in that the clean water dispenser (40) with two outlet channels comprises, at its inlet, a deflector (60) which prevents the creation of turbulence in the stream of water supplying this dispenser.
12. Electrical household appliance such as a dish-washer, a washing machine, characterized in that it comprises a water level regulating device (10) according to one of Claims 1 to 11, mounted as communicating vessels with its tank (3).

Images